/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#ifndef OCEANBASE_OB_SQL_EXPR_CASE_H_
#define OCEANBASE_OB_SQL_EXPR_CASE_H_

#include "sql/engine/expr/ob_expr_operator.h"

namespace oceanbase {
namespace sql {

#define CHECK_WHEN_EXPR_TYPE (1ULL)
#define NEED_CHECK_WHEN_EXPR_TYPE(flag) (((flag)&CHECK_WHEN_EXPR_TYPE) != 0)

class ObExprCase : public ObExprOperator {
public:
  explicit ObExprCase(common::ObIAllocator& alloc);
  virtual ~ObExprCase();

  virtual int calc_result_typeN(
      ObExprResType& type, ObExprResType* types_stack, int64_t param_num, common::ObExprTypeCtx& type_ctx) const;
  virtual int calc_resultN(
      common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num, common::ObExprCtx& expr_ctx) const;
  int calc(common::ObObj& result, const common::ObObj* objs_stack, int64_t param_num,
      const ObExprResType& expected_type, common::ObExprCtx& expr_ctx) const;

  static int calc_case_expr(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& res_datum);
  virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;
  static int is_same_kind_type_for_case(const common::ObIArray<ObExprResType>& type_arr);

private:
  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprCase);
};
}  // namespace sql
}  // namespace oceanbase
#endif  // OCEANBASE_OB_SQL_EXPR_CASE_H_
